1. Field of the Invention
The present invention relates to a lubricating system for an internal combustion engine for restricting the overall height of the internal combustion engine.
2. Description of Background Art
A lubricating system for an internal combustion engine is known, for example, as described in Japanese Patent Publication No. Sho 62-49448 entitled xe2x80x9cOil Piping Structure of Engine.xe2x80x9d
In FIG. 3 of the above-mentioned publication, there is shown a structure in which the bottom 20a of a crankcase forms an oil pan, an oil strainer 27 is disposed in the oil pan, and an oil pump 25 is connected to an upper portion of the oil strainer 27.
The technology disclosed in the publication has the following disadvantages: the oil strainer 27 is trapezoidal in side view; a communicating passage (no symbol) for communication of the oil strainer 27 and the oil pump 25, and the oil pump 25 are stacked vertically from the bottom 20a of the crankcase to the upper side, and, therefore, the vertical size of the lubricating system becomes large, resulting in that the overall height of the engine becomes large, and the vehicle on which the engine is mounted is necessarily large.
Accordingly, it is an object of the present invention to provide a lubricating system for an internal combustion engine which restricts the overall height of the internal combustion engine by reducing the vertical size of the lubricating system.
In order to attain the above-mentioned object, an internal combustion engine is provided that includes a pair of case halves that are coupled to constitute a crankcase that form an oil pool in the bottom of the crankcase that is fed through a strainer and an oil pump to various portions. The crankcase is provided with a ceiling portion for shutting off the upper side of the oil pool. A window is opened in the ceiling portion of one of the case halves. The strainer is formed in a flat plate like shape and the flat plate like strainer is fitted in the window. One of the case halves is provided with an oil passage through which the oil having passed through the strainer flows roughly horizontally to a suction port of the oil pump. The ceiling portion of one of the case halves is provided with a cutout portion by not casting at a position where the ceiling portion of one of the case halves and the oil pump are adjacent to each other. A plug is fitted in the cutout portion.
The flat plate like strainer is fitted in the window opened in the ceiling portion above the oil pool. One of the case halves is provided with the oil passage through which the oil having passed through the strainer flows roughly horizontally to the oil pump suction port, and one of the case halves is provided with the cutout by not casting at the position where the ceiling portion of one of the case halves and the oil pump are adjacent to each other, whereby the vertical size from the oil pool to the oil pump suction port is reduced as much as possible, and the overall height of the internal combustion engine is restricted.
The present invention includes a plug that is molded as one body with an O-ring for sealing the joint portion of the oil pump suction port and an end portion of the oil passage.
By molding the plug as one body with the O-ring, the number of component parts is reduced, and production cost of the internal combustion engine is reduced.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.